Such metal foil elements are known, e.g., from No. SE-A-7713250-4, and are being used more and more for various heating purposes, e.g., for heating car seats or other flexible surface elements, or for heating rigid surfaces, possibly having a complicated geometrical, in particular curved shape. For such purposes, it is usually essential that the loop-formed metal foil element cover a relatively large surface area, although the mutually adjacent parts of the loop element should preferably be well separated from each other, e.g., to enable stretching during assembly or use of the element.
The manufacture of such loop elements with relatively sparsely distributed loop portions has hitherto involved a great waste of material, since the material between the loop portions was discarded. Moreover, conventional methods of printing and etching of loop patterns are extremely complicated and cumbersome.
The object of the invention is to achieve a manufacturing method in which the waste of material is considerably reduced and which, moreover, permits an especially simple method of manufacture, namely, punching.